Article with protective coating thereon

DETAILED DESCRIPTION The present invention is directed to a metallic substrate having a multi-layer coating disposed or deposited on its surface.
More particularly, it is directed to a metallic substrate, particularly brass, having deposited on its surface multiple superposed metallic layers of certain specific types of metals or metal compounds or metal alloys.
The coating is decorative and protective, e.
g.
, provides corrosion and wear resistance.
The coating simulates the appearance of highly polished brass, i.
e.
has a brass color tone.
Thus, an article surface having the coating thereon simulates a highly polished brass surface.
A first layer deposited directly on the surface of the substrate is comprised of nickel.
The first layer preferably consists of two different nickel layers such as a semi-bright nickel layer deposited directly on the surface of the substrate and a bright nickel layer superimposed over the semi-bright nickel layer.
Disposed over the nickel layer is a layer comprised of gold.
This gold layer is thinner than the nickel layer.
Over the gold layer is a layer comprised of ruthenium.
Over the ruthenium layer is a layer comprised of a non-precious refractory metal such as zirconium, titanium, hafnium or tantalum, preferably zirconium or titanium.
A top layer comprised of a zirconium compound, titanium compound, hafnium compound or tantalum compound, preferably a titanium compound or a zirconium compound such as zirconium nitride, is disposed over the refractory metal layer, preferably zirconium layer.
The nickel, gold and ruthenium layers are preferably applied by electroplating.
The refractory metal layer such as zirconium layer and refractory metal compound layer such as zirconium compound layer are applied by vapor deposition such as sputter ion deposition.